What role for the victims in the prevention of radicalism?

Victims of terrorism are sometime being used by the authorities to deliver a speech towards a (potentially) radicalized audience. Main ideas are the following: victims are usually being dehumanized by the perpetrators of attacks and the narration of their ordeal gives them a face, and the confrontation between a victim and a extremist causes a “narrative chock” that can help, using emotion, to support a message. The RAN even published in 2015 a handbook supporting this idea.
Being himself a victim (former IS hostage in Syria for almost a year), the presenter, now chairman of a consulting company based in Marseilles, France, argues that this approach has limits and that the victims are mostly important to prevent a polarisation of societies and advocate to keep together moderate persons from all communities rather than addressing radicalized individuals.
This presentation is based mostly on the French experience, especially recalling both collective (victims associations, like 13onze15 for Bataclan attack survivors and families) and individual (Antoine Leiris’ book Meinen Hass bekommt ihr nicht, for the German edition) initiatives to highlight the benefits of some victims’ voices and to suggest good practices.